OK, I been trying to solve a different problem. Now you say there is a server involved. Now server configuration is involved besides a possible problem with the html and jar file.

To isolate the problem, Have you tried copying the html file and the jar file to a local folder and opening the html file with the browser? That is don't use a server, only the browser reading and html file.

I found the missing jar file with the swing components, compiled your program with it, added the jar file reference to the html file, opened the html file in a browser and it displayed the three text fields and the button. I enter some numbers, press the button and I get a message about weight. It appears to work.

So what is different about your setup? It's on an iMac?

Using a server can require setup. Reading an html file from a local folder doesn't.

I don't see why you have to put it inside the BMI.jar? As long as you call the correct path, it shouldn't matter where it is.

Also, it seems to have worked for Norm doing it the way I have.

I have however just added the classes from within the swing layout jar directly into the BMI.jar and it goes back to displaying the error message on the page. When I do it my way, the applet starts but I don't see it (however, Norm does on his computer).

Go back to basics: Write the simple "Hello World" applet and see if that works. If not, then you have a system/installation problem. If it does work, then try working with your program. I removed all the layout stuff generated by your IDE and added a simple label to your applet and got a simple gray box with the label showing. Then move on from there to see why the generated layout doesn't work.

Go back to basics: Write the simple "Hello World" applet and see if that works. If not, then you have a system/installation problem. If it does work, then try working with your program. I removed all the layout stuff generated by your IDE and added a simple label to your applet and got a simple gray box with the label showing. Then move on from there to see why the generated layout doesn't work.

I've kind of put this "project" to the side at the moment as i'm trying to get my own web server up and running correctly so I can host some java projects. I know I have had an applet working on here not so long ago but will give a simple applet another go again at some point.

I will give you both some rep (if that's possible) as you have both been helpful.

I don't see why you have to put it inside the BMI.jar? As long as you call the correct path, it shouldn't matter where it is.

Also, it seems to have worked for Norm doing it the way I have.

I have however just added the classes from within the swing layout jar directly into the BMI.jar and it goes back to displaying the error message on the page. When I do it my way, the applet starts but I don't see it (however, Norm does on his computer).

applets and sys PATH are big difference :)
you should not just add classes but the the jar lib packages' structure accouring to your applet import refs...
applets are not like servlets so they don't use sys PATH things ;)

If my answer helped you. Please click my "REP" button and add a comment
Have a Good Java Coding :)

I don't see why you have to put it inside the BMI.jar? As long as you call the correct path, it shouldn't matter where it is.

Also, it seems to have worked for Norm doing it the way I have.

I have however just added the classes from within the swing layout jar directly into the BMI.jar and it goes back to displaying the error message on the page. When I do it my way, the applet starts but I don't see it (however, Norm does on his computer).

I do hope you'll see that now :)

I think that shouldn't be a personal JRE or OS problem so...
I have added the netbeans layout manager right into the applet jar just to refresh my fingers... anyway, I want you to run the html file and see if the applet runs!

I was testing it with Opera. So I recommend you to run it with Opera, too, because Opera runs Applets not with some plugins but with JRE

That's not true on Windows. I was able to have two jar files referenced in the archive= parameter of the <APPLET tag and it worked.

Have you tried REMOVING all the org.jdesktop. GUI components from the applet and add only a simple JLabel to the GUI so that all the classes you need are in the JRE and your jar file?
Something like this:

Cheers WebUser, that runs fine in my browser now. I tried to add some rep for you but as I already did so yesterday, it won't allow me too.

I still don't fully understand why the layout stuff has to be put directly into the jar and can't be called but as long as I know that for the future, I should be fine!

I believe this thread can be marked as solved now.

You have to understand that you must add all required NetBeans layout classes not because "it is always must be so" but because of NetBeans specific absolute layout manager I mentioned before. It is NetBeans stuff only :) default JRE doesn't contain this layout manager so you have to make sure to have one right in your applet jar ;) It's easy.
Just imagine like a... you want to use apachePOI or something outer of JRE... So in that case you have to add all required classes right into your jar too ;)

If my answer helped you. Please click my "REP" button and add a comment
Have a Good Java Coding :)